In recent years, a type of mobile communications network known as an ad-hoc network has been developed. In this type of network, each mobile node is capable of operating as a base station or router for the other mobile nodes, thus eliminating the need for a fixed infrastructure of base stations. As can be appreciated by one skilled in the art, network nodes transmit and receive data packet communications in a multiplexed format, such as time-division multiple access (TDMA) format, code-division multiple access (CDMA) format, or frequency-division multiple access (FDMA) format.
More sophisticated ad-hoc networks are also being developed which, in addition to enabling mobile nodes to communicate with each other as in a conventional ad-hoc network, further enable the mobile nodes to access a fixed network and thus communicate with other mobile nodes, such as those on the public switched telephone network (PSTN), and on other networks such as the Internet. Details of these advanced types of ad-hoc networks are described in U.S. patent application Ser. No. 09/897,790 entitled “Ad Hoc Peer-to-Peer Mobile Radio Access System Interfaced to the PSTN and Cellular Networks”, filed on Jun. 29, 2001, now U.S. Pat. No. 7,072,650, in U.S. patent application Ser. No. 09/815,157 entitled “Time Division Protocol for an Ad-Hoc, Peer-to-Peer Radio Network Having Coordinating Channel Access to Shared Parallel Data Channels with Separate Reservation Channel”, filed on Mar. 22, 2001, now U.S. Pat. No. 6,807,165, and in U.S. patent application Ser. No. 09/815,164 entitled “Prioritized-Routing for an Ad-Hoc, Peer-to-Peer, Mobile Radio Access System”, filed on Mar. 22, 2001, now U.S. Pat. No. 6,873,839, the entire content of each being incorporated herein by reference.
Ad-hoc networks typically comprise a plurality of nodes that collectively define a path from a mobile client to a destination node, or another network node by way of one or more wireless network nodes. Generally, a “channel” is established from each node to another defining the path to the network access node, which, in turn, provides access to an external network, such as the Internet. The channel may also be from one node to another in the same network when the destination is a user associated with the node.
As can be appreciated from the nature of wireless “ad hoc” networks such as those discussed above, a careful assignment of frequencies and channels is important for minimizing interference between nodes using the same frequency or channels in a network, and for maximizing the performance and efficiency of the network. In this regard, traditional methods of frequency channel assignment become difficult, for example, when only a small number of channels are available. Moreover, frequency channel assignments become difficult when the number of nodes exceeds the number of available channels.
Several techniques exist which address frequency channel assignment in the context of wireless “ad-hoc” networks. U.S. Patent Application 2004/0157613, for example, discloses a method for reducing co-channel and adjacent channel interference via self-selection of Radio Frequency Channels. Moreover, a publication by DeCouto et al. entitled “A High-Throughput Path Metric for Multihop Wireless Routing,” M.I.T. Computer Science and Artificial Intelligence Laboratory, 2003, discloses an expected transition count (ETX) metric which identifies a relationship that is inversely proportional to the packet completion rate, but it does not account for variable data rates or signaling overhead.
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